Protective association of Klotho rs495392 gene polymorphism against hepatic steatosis in non-alcoholic fatty liver disease patients

Background/Aims

Non-alcoholic fatty liver disease (NAFLD) is closely associated with metabolic dysfunction. Among the multiple factors, genetic variation acts as important modifiers. Klotho, an enzyme encoded by the klotho (KL) gene in human, has been implicated in the pathogenesis of metabolic dysfunctions. However, the impact of variants in KL on NAFLD risk remains poorly understood. The aim of this study was to investigate the impact of KL rs495392 C>A polymorphism on the histological severity of NAFLD.

Methods

We evaluated the impact of the KL rs495392 polymorphism on liver histology in 531 Chinese with NAFLD and replicated that in the population-based Rotterdam Study cohort. The interactions between the rs495392, vitamin D, and patatin-like phospholipase domain containing 3 (PNPLA3) rs738409 polymorphism were also analyzed.

Results

Carriage of the rs495392 A allele had a protective effect on steatosis severity (odds ratio [OR], 0.61; 95% confidence interval [CI], 0.42–0.89; P=0.010) in Chinese patients. After adjustment for potential confounders, the A allele remained significant with a protective effect (OR, 0.66; 95% CI, 0.45–0.98; P=0.040). The effect on hepatic steatosis was confirmed in the Rotterdam Study cohort. Additional analysis showed the association between serum vitamin D levels and NAFLD specifically in rs495392 A allele carriers, but not in non-carriers. Moreover, we found that the rs495392 A allele attenuated the detrimental impact of PNPLA3 rs738409 G allele on the risk of severe hepatic steatosis.

Conclusions

The KL rs495392 polymorphism has a protective effect against hepatic steatosis in patients with NAFLD.

Relationship between Vitamin D and Nonspecific Low Back Pain May Be Mediated by Inflammatory Markers

BACKGROUND

Vitamin D deficiency has been linked to nonspecific low back pain (Ns-LBP); however, the role of inflammation as a possible mediator between vitamin D levels and Ns-LBP is not well understood.

OBJECTIVE

To explore the mediating effects of inflammatory markers on the relationship between vitamin D levels and pain outcomes.

STUDY DESIGN

A retrospective study.

SETTING

Department of Spinal Surgery of a hospital affiliated to a medical university.

METHODS

In this cross-sectional study, we selected patients with non-specific acute low back pain (Ns-ALBP, n = 60) and non-specific chronic low back pain (Ns-CLBP, n = 78), as well as 60 people without Ns-LBP as controls, from January 2018 to January 2019. Serum 25(OH)D and inflammatory marker levels were examined. Regression and causal mediation analysis were used to evaluate the mediating effects of inflammatory markers on the association between vitamin D and pain.

RESULTS

Mean serum concentrations of vitamin D in the control, Ns-ALBP, and Ns-CLBP groups were 25.70 ± 10.04, 21.44 ± 8.46 and 18.25 ± 8.05 ng/mL, respectively (P < 0.001). After adjustment for clinical factors, vitamin D deficiency was associated with Ns-LBP (P < 0.05); however, when the interleukin 6 (IL-6) level was added to the multivariable models, the association was no longer significant in Ns-CLBP patients. Mediation analysis estimated the overall mediated effect as -0.461 (P < 0.001) in Ns-CLBP patients, and the intermediary effect of IL-6 was 0.045.

LIMITATIONS

A retrospective study may include inevitable bias. More sensitive biomarkers were not investigated in this study. Pain intensity evaluation using the visual analogue scale is inevitably subjective.

CONCLUSION

Patients with Ns-LBP had lower vitamin D and higher inflammatory marker levels. This association between hypovitaminosis D and Ns-CLBP may be mediated by IL-6. Therefore, large-scale clinical trials are warranted to investigate the clinical efficacy of vitamin D supplementation for decreasing inflammation and relieving Ns-LBP.

Vitamin D Status and Risk of All-Cause and Cause-Specific Mortality in a Large Cohort: Results From the UK Biobank

CONTEXT

Although an inverse association between vitamin D status and mortality has been reported in observational studies, the precise association shape and optimal vitamin D status remain undetermined.

OBJECTIVE

To investigate the association between vitamin D status and risk of all-cause and cause-specific mortality and estimate optimal serum 25-hydroxyvitamin D [25(OH)D] concentrations.

DESIGN

Prospective cohort study.

SETTING

UK Biobank.

PARTICIPANTS

365 530 participants who had serum 25(OH)D measurements and no history of cardiovascular disease (CVD), cancer, or diabetes at baseline (2006-2010).

MAIN OUTCOME MEASURES

All-cause and cause-specific mortality.

RESULTS

During a median follow-up of 8.9 (interquartile range: 8.3-9.5) years, 10 175 deaths occurred, including 1841 (18.1%) due to CVD and 5737 (56.4%) due to cancer. The multivariate analyses revealed nonlinear inverse associations, with a decrease in mortality risk appearing to level off at 60 nmol/L of 25(OH)D for all-cause and CVD deaths and at 45 nmol/L for cancer deaths. Compared to participants with 25(OH)D concentrations below the cutoffs, those with higher concentrations had a 17% lower risk for all-cause mortality (hazard ratio [HR]: 0.83, 95% confidence interval [CI]: 0.79-0.86), 23% lower risk for CVD mortality (HR: 0.77, 95% CI: 0.68-0.86), and 11% lower risk for cancer mortality (HR: 0.89, 95% CI: 0.84-0.95).

CONCLUSIONS

Higher 25(OH)D concentrations are nonlinearly associated with lower risk of all-cause, CVD, and cancer mortality. The thresholds of 45 to 60 nmol/L might represent an intervention target to reduce the overall risk of premature death, which needs further confirmation in large clinical trials.

It's Not All Sunshine: Non-sun-related Melanoma Risk-factors

There is increasing evidence that the behaviour of naevi and melanoma is under significant genetic and/or epigenetic control. Melanoma tumours behaves similarly all over the world. Many genes have now been implicated in melanoma risk and naevi number. Embryogenesis has also been important in the discovery of links between several neurological diseases and melanoma susceptibility. Telomere biology, which regulates cell senescence, is increasingly relevant in melanoma. Melanoma is often found in the context of family cancer syndromes and the identification of these families is important as screening for cancer will save lives. Melanoma is also one of the most immunogenic cancer as the behaviour of naevi and melanoma differ in patients with vitiligo or eczema. The search for non-sun related melanoma risk factors should continue as it is likely to lead to important discoveries which will, in turn, have an impact on therapeutic targets for this tumour.

Possible role of vitamin d in pathogenesis of lichenoid dermatoses (a review of literature)

OBJECTIVE

The aim of the study was search and analysis of the data of review, experimental and clinical scientific and medical publications on the issues of the possible role of VD inpathogenesis of lichenoid dermatoses.

PATIENTS AND METHODS

Materials and methods: An analysis of the studying of the scientific and medical literature was shown. Searching was carried out through the PubMed/MEDLINE portal from the databases of the National Center Biotechnology Information, Web of Science Core Collection, U. S. National Library of Medicine, National Institute for Health and Clinical Excellence, as well as the portals «Scientific Electronic Library eLIBRARY.RU», «Russian Science Citation Index (RSCI)» and «Index Copernicus».

CONCLUSION

Conclusions: The results of studies had convincingly demonstrated that deficiency of VD in the blood, decrease vitamin D receptors activity can lead to development of lichenoid dermatoses.

[Vitamin D - a geriatric point of view]

Elderly people more often suffer from vitamin D insufficiency. It is caused by insufficient supply with diet and scarce sun exposure, due to life style. This is a very common situation in Poland and worldwide. Vitamin D influences functioning of many various organs. Its deficiency may cause bone mineralization disorders, osteomalacia, osteoporosis, muscle weakening, which can result in higher risk of falls. Its influence on cardiovascular diseases, type 2 diabetes and cognitive functions is widely discussed. Supplementation is crucial in elderly population. It should be administrated all year, with adjustement of dose to age and weight. Initial blood concentration is not required. An appropriate sun exposure is recommended. Treatment of vitamin D deficiency should be intensive and last for several months. Although the doses are high, no adverse effects were observed.

The potential role of vitamin D enhanced foods in improving vitamin D status

Low vitamin D intake and status have been reported worldwide and many studies have suggested that this low status may be involved in the development of several chronic diseases. There are a limited number of natural dietary sources of vitamin D leading to a real need for alternatives to improve dietary intake. Enhancement of foods with vitamin D is a possible mode for ensuring increased consumption and thus improved vitamin D status. The present review examines studies investigating effects of vitamin D enhanced foods in humans and the feasibility of the approach is discussed.